A need exists for a system of handling phototransparency slides which does not require bulky and expensive storage trays and allows "stack-loading" without requiring a projectionist to handle individual slides.
The currently available techniques for slide storage and handling all involve dedicated storage magazines. Two generic categories can be defined:
(a) Individual slide magazines--These devices are typified by the familiar carousel-magazine design; in which each slide is individually stored in an isolated compartment within the carousel. The carousel attaches to the projector mechanism and serves as a dedicated storage and transfer magazine. Of the two categories, this technique represents the lowest slide storage density, the most expensive system and is characterized by intermediate subject continuity. PA1 (b) Stack magazines--In this case, individual, dedicated magazines store slide stacks, usually consisting of about 40 slides as required by most current stack-loading projection machines. One example of the stack magazine system is shown in U.S. Pat. No. 3,926,514, entitled "Slide Projector Loading--Unloading Station," Costanza, et al. The system shown in the referenced patent is marketed as the Bell & Howell "Slide Cube System". In this system, cubical magazines, each containing one stack, are individually attachable to a specific Bell & Howell projector and serve as dedicated storage and transfer compartments. Another example of the stack magazine category is a Kodak product called "Slide Clips". This device is similar to the "Slide Cube" system but operates only with Kodak stack-loading projectors. Comparatively, this category represents intermediate storage density, intermediate expense and the poorest subject continuity and organization.